TUNE-UPS AND TRYOUTS

From St. Louis to New Delhi last week, cameras caught some famous people in pursuits they are not famous for: the spiritual leader of 20 million Moslems taking a competitive spin down a slalom run at St. Moritz; the Prime Minister of a vast republic testing his cue stick skill on the green baize table of sport and diplomacy; a pair of skating champions in sisterly song at the family piano; a veteran baseball player in the uniform of the gymnasium. Tuning up or trying out, these celebrities provided the photograph album of the young year 1960 with some fresh and novel entries.

Gymnast is Stan Musial, 39, of the St. Louis Cardinals, who hopes that with winter exercise regimen he can have a better baseball summer than last year. Following a six-week calisthenics program prescribed by Cardinal Trainer Bob Bauman, he finds himself "doing exercises I haven't done since I was a kid." He found that, from lack of practice, he could do only four push-ups at first. His aim is 25. "It looks easy," said Stan, "but, man, it isn't."

Singers are World Champion Figure Skater Carol Heiss, 20 (left), and sister Nancy, 18, both of them girls to be reckoned with in Olympic competition until Nancy was sidelined with a fractured ankle a fortnight ago. One event in which they can still perform together is the piano duet, and in this one they are conducted in a favorite, O Tannenbaum, by their father. Nancy hopes to be at Squaw Valley as Carol goes for the figure skating gold medal.

Skier on the slopes of St. Moritz is Aga Khan, 23, Shi'ite Moslem leader and onetime Harvard soccer player. Despite meager time for ski practice, he did well enough in early events of British Alpine championships, including a third-place finish in slalom, to be considered for the British team at the Squaw Valley Olympics. His outstanding form was the talk of St. Moritz, but, to the sorrow of his fans, a tumble, and resulting lost time, ruled him out.

Snooker-shooting statesman is India's Prime Minister Jawaharlal Nehru. On a visit to the new Soviet embassy in New Delhi he was shown the swimming pool, theater and chess room, then invited to try his hand in the billiard room. He hit only a few informal shots, but his stance and cue handling suggested he was no stranger to the game. Observing' the Prime Minister are Soviet embassy aides and Nehru's daughter, Indira, wife of Pheroze Gandhi.